New Path to Solar Energy Via Solid-State Photovoltaics

A newly discovered path for the conversion of sunlight to electricity could brighten the future for photovoltaic technology

Researchers with Lawrence Berkeley National Laboratory (Berkeley Lab) have found a new mechanism by which the photovoltaic effect can take place in semiconductor thin-films. This new route to energy production overcomes the bandgap voltage limitation that continues to plague conventional solid-state solar cells.

Working with bismuth ferrite, a ceramic made from bismuth, iron and oxygen that is multiferroic -- meaning it simultaneously displays both ferroelectric and ferromagnetic properties -- the researchers discovered that the photovoltaic effect can spontaneously arise at the nanoscale as a result of the ceramic's rhombohedrally distorted crystal structure. Furthermore, they demonstrated that the application of an electric field makes it possible to manipulate this crystal structure and thereby control photovoltaic properties.

"We're excited to find functionality that has not been seen before at the nanoscale in a multiferroic material," said Jan Seidel, a physicist who holds joint appointments with Berkeley Lab's Materials Sciences Division and the UC Berkeley Physics Department. "We're now working on transferring this concept to higher efficiency energy-research related devices."